Development of a Model View Definition (MVD) for Thermal Comfort analyses in Commercial Buildings using BIM and EnergyPlus

Layout

1. Introduction

2. Standardised Methods

3. Methodology

4. Demonstration and Results

5. Conclusion and Future Work

1. Introduction

Buildings don't operate as intended, with poor prediction as a key factor

32%EU 19%

CO2

25%

EU aim to achieve 25% reduction in energy use by 2050

EU Energy 36%

Up to 32% of global energy use

➢ 80% of the energy used in commercial office spaces, is typically used for maintaining optimal comfort levels (heating, cooling, ventilating, and lighting).Source : SEAI,2015

Source : EU Climate Action, 2016

The buildings where we spend our time, have a significant impact on our health, comfort and wellbeing

(ASHRAE) define thermal comfort as “the condition of the mind in which satisfaction is expressed with the thermal environment”

Of our time in indoor environment.

Deaths in Europe during the heat wave of August 2003.

Consumes by the UK employees to control their environment

Workers tended to lose their productivity during work hours under uncomfortable condition

80 -90 %

70,000

£13Bil./year

Productivity

Demand for low energy & comfortable buildings mandates more complex building design with stringent performance criteria

Users

Equipm-ents

Environm-ent

HAVC Systems

Building Envelope

➢ Predict the annual energy performanceof a building .

➢ Can be used to predict differences in energy consumption for different design alternatives.

➢ Predict the Thermal comfort level of a building occupants.

➢ Provides designers with the necessary information about a building design and indoor enverioment

BEPS (Building Energy Performance

Simulation)

\

INPUT DATA

Performance Simulation Results (e.g. Total Energy Consumption & Thermal Comfort level)

Building geometry HVAC System Weather condition Internal loads

Building Energy Performance Simulation BEPS creation (e.g. Energy Plus)

The basic parameters of input data for energy simulation

Automatically generating

Manually re-entering

Still common practiceUsually resulting in:➢ Missing important information ➢ Misplaced or distorted building elements➢ Time consuming and cost of labour.➢ Cause inaccuracy of the output.

Building Energy Performance Simulation

(BEPS)

Problem Statement

Building Information Modelling (BIM)

2. Standardised Methods

IFC

➢ Industry Foundation Classes (IFC)1. Most commonly used open and complete data format

2. Objects are represented with properties and references to others objects

IDM

➢ Information Delivery Manual (IDM)1. Provides a standardized method

2. What information is being exchanged

3. Who needs the information extracted

4. Which point in time this information is needed

5. Provides a graphical representation of the exchange process

MVD

➢ Model View Definition (MVD)1. Definition of a subset of IFC that satisfies a specific exchange scenario (e.g.

Thermal comfort)

Standardised methods for the integration of BIM and BEPS tools for thermal comfort analysis

1. Description of the analysis process

IDM

co

mp

on

ents

2. Graphic translation of the Data flow among stakeholders

3. Description of the information to be exchanged

BusinessUse Case

Process Map

ExchangeRequirements

4. Technical specification of the Exchange Requirement (needed to develop a MVD).

ExchangeRequirement

Model

Standardised methods for the integration of BIM and BEPS and Information Delivery Manual (IDM)

Res

earc

h T

asks

2. Define the process responsible actors and the data flow between the design stakeholders

3. Provides a description of the information that support thermal comfort analysis in non-technical terms.

4.Identifying entities and property sets in the existing IFC4 schema that support thermal comfort analysis.

1. BIM IFC creation model In order to define the process map and the exchange requirements

Can be delivered in electronic format (.ifc, .ifcxml, .xml)

Standard, open and reusable data structure, based on the IFC schema.

It represents a subset of the entire IFC data set.

Our MVD➢ Aims to be a unique

container able to collect those pieces of information needed for Thermal comfort analysis across the different project stages.

➢ The output of IFC files includes only the exchange requirements defined for that specific analysis, thus filtering unrelated information.

IFC BIM model(ISO16739:2013)

3. Methodology

Task 1: BIM creation

➢ This office is one of the typical officeslocated in the School of Mechanical &Materials Engineering, University CollegeDublin (UCD).

➢ This use case consists of a single thermalzone and full description for buildingelements and their properties includingHVAC system.

1. Business Use Case

Task 2: Process Map of information exchange among design team

2. Define data exchange mapping process

BIM

IF

CE

xch

an

ge

Re

qu

ire

me

nts

Sp

ecific

ation

Arc

hite

ct

Bu

ildin

g

Se

rvic

es

En

gin

ee

rs

Detailed space layout

Space classification

(Space function)

Exchange Requirements for

space layout

Exchange Requirements for

HVAC system

HVAC Design

Define space layout

The final space design

arrangements

Space layout in eraly desinge stage

The traditional design process

a BIM collaborative environment

Task 3.2: Identifying entities and property sets in the existing IFC4 schema that support thermal comfort analysis.

3. Description of the information to be exchanged

Task 3.1: Provides a description of the information that support thermal comfort analysis in non-technical terms .

➢ A set of information that needs to be exchanged between processes➢ They are general statements of requirement➢ They are not specific to an IFC release.

Task 3.3: Identifying any missing entities or property from the IFC schema that support thermal comfort analysis.

Exiting entity in IFC4

Exiting properties in IFC4

Proposed properties to add

IfcMaterial

Property Sets

Pset_MaterialEnergy Pstc_MaterialThermal

Property

MoistureCapacity

ViscosityTemperature

TemperatureDerivative

Property

SolarRefraction

AbsorptionCoefficient

CoefficientOfHeatTransfer

3. Description of the information to be exchanged

New property set for Material Thermal (Pstc_MaterialThermal)

Proposed properties to add.

Entity Property Set Property Data Type Unit

IfcWall Pset_WallCommon ThermalTransmittance ThermalTransmittanceMeasure W/m².K

Task 3.4: Define the Exchange Requirements needed to develop MVD for Thermal comfort analysis

3. Description of the information to be exchanged

1 2 3 4

1

2

3 45

5

Task 4: Create data extraction (MVD) for Thermal Comfort analysis

4. MVD Creation using IFC Documentation Generator (IfcDoc)

Pro

ject U

nits

Pro

ject R

ep

rese

ntatio

n C

on

text

Pro

ject C

lassification

Info

rmatio

n

Pro

ject D

ocu

me

nt In

form

ation

Ob

ject T

ypin

g

Pro

pe

rty Sets

Pro

pe

rty Sets fo

r ob

ject

Pro

pe

rty Sets fo

r Typ

es

Qu

antity Se

ts

Ob

ject A

ttribu

tes

Ob

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ser Id

en

tity

Ob

ject P

red

efin

ed

Typ

e

Do

or A

ttribu

tes

Win

do

w A

ttribte

s

Ob

ject T

ype

Attrib

ute

s

Mate

rial Layer Se

t

Mate

rial Pro

file Se

t

Mate

rial Co

nstitu

en

t Set

Ele

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nt C

om

po

sition

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Spatial C

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Spatial D

eco

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Ne

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Typ

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lem

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t Aggre

gation

Ob

ject A

ssignm

en

t

Pro

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me

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Spatial Stru

cture

Spatial C

on

tainm

en

t

Space

Bo

un

darie

s

Pre

du

ct Placm

en

t

Pro

du

ct Local P

lacem

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Pro

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e P

lacme

nt

Pro

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om

etric R

ep

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Co

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etry

Foo

tPrin

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etry

Re

fere

nce

Ge

om

etry

Bo

dy G

eo

me

try

Mate

rial De

finitio

n

Mate

rial Pro

pe

rites

IfcBuilding

IfcBuildingElement

ifcBuildingStory

IfcColumn

IfcCurtainWall

IfcDistributionElement

IfcDistributionElementType

IfcDistributionFlowElement

IfcDoor

IfcElement

IfcElementType

IfcFurniture

IfcLightFixture

IfcMaterial

IfcObject

IfcProduct

IfcProject

IfcRoof

IfcRoot

IfcSite

IfcSlab

IfcSpace

IfcSpaceHeater

IfcSpatialStructureElement

IfcWall

IfcWindow

IfcZone

Incompatible Within scope but not defined Not relevant but has been defined

Set as mandatory for export function Set as optional for export function

➢ To date this work has identified11 objects.

➢ Over 109 properties relevantfor thermal comfort analysis.

➢ IfcDoc improve the consistent and computer-interpretable definition of (MVD) as true subsets of the IFC Specification.

Incompatible

Set as mandatory for export function

Set as optional for export function

Not relevant but has been defined

Within scope but not defined

4. Demonstration

With use cases that enable control over the export to IFC we specified the necessary information exchange

IfcSpace

➢ IfcSpace where the most properties for thermal comfort were defined.

IfcSpace

Pset_ SpaceOccupancyRequirements

OccupancyType IfcLabel --

OccupancyNumber IfcCountMeasure --

OccupancyNumberPeak IfcCountMeasure --

OccupancyTimePerDay IfcTimeMeasure --

AreaPerOccupant IfcAreaMeasure m²/p

MinimumHeadroom IfcLengthMeasure mm

Pset_ SpaceThermalLoad

Activity level IfcPowerMeasure met

EquipmentSensible IfcPowerMeasure kW

Lighting IfcPowerMeasure kW

AirExchangeRate IfcPowerMeasure m³/s

DryBulbTemperature IfcPowerMeasure °C

RelativeHumidity IfcPowerMeasure %

TotalSensibleLoad IfcPowerMeasure W

InfiltrationSensible IfcPowerMeasure W

Entity Property Set Property Data Type Unit

➢ IfcSpace where the most properties for thermal comfort were defined.

5. Conclusion & Future Work

Conclusion

➢ Providing thermal comfort for a building's occupants remains one of the main aims of designing and creating a working or living space.

➢ Thermal comfort simulation analysis requires detailed specification of the data and information that needs to be exchanged to support these processes.

➢ The outputs of this work will contribute to:

1. Data to be transferred in a higher level of automation

2. Less manual work, lower risk of human error and better information quality

3. Achieve optimum and reliable results of thermal comfort analysis

4. Reduce cost and labour intensive as well as complexity.

Future Work

➢ The next part of this research will focus on extend this methodology to account for CFD modelling based simulations of thermal comfort.

➢ Further specification of the MVD to include all relevant building components.

➢ Extension of the IFC schema for missing concepts, entities and properties.

➢ The proposed MVD will be applied and tested in a full-scale building.

➢ Submit the MVD to buildingSMART to become an official MVD.

Fawaz AlshehriFawaz Alshehri